The relation of biogenic amines, including the indoles (serotonin, melatonin and tryptamine) and the catechols (dopamine, norepinephrine and epinephrine), to behavior are considered in several contexts. The primary concern of this program is with these compounds as neuroregulatory agents in brain, functioning as neurotransmitters or neuromodulators. We are involved in a five-pronged research plan, including studies centered about: I. Biochemical regulation; II. Analytical chemistry; III. Endocrine processes; IV. Behavioral neurochemistry; and V. Clinical studies. The methods which have been used are primarily those of biochemical pharmacology, but those methods are related to a variety of behavioral and clinical areas. We are interested in improving analytical procedures and for many of our studies would use analytical mass fragmentography. The animal behaviors with which we are particularly concerned include pain and sleep mechanisms. The focus for the clinical studies is a concern for severe psychiatric illnesses. The clinical studies involve direct testing of specific hypotheses of the relationships between psychiatric illness and biochemical processes through examination of cerebrospinal fluid and precursor and inhibitor loading studies.